Cut and stack labels of laminated film

ABSTRACT

A cut and stack label includes a layer of polymer film printing stock having a first face carrying a printed message and a second, opposite face, a clear polymer film laminated to the first face over that printed message and a coating of an anti-static formulation over the clear polymer film and/or the second face. An optional dusting or layer of offset powder may also be provided.

This application is a 371 of PCT/US02/20585 filed Jun. 27, 2002 whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/301,768 filed Jun. 28, 2001.

TECHNICAL FIELD

The present invention relates generally to the product labeling fieldand, more particularly, to a laminated polymer film label havingsufficient stiffness and anti-static properties to run in existing cutand stack labeling equipment as well as a method for the production ofsuch a label.

BACKGROUND OF THE INVENTION

There is a growing consumer preference for food, beverage and householdproducts packaged in plastic containers. This is because plasticcontainers offer the consumer a number of convenient benefits including,but not limited to, portability, resealability, safety, light weight andcontourability for a comfortable grip.

Plastic containers, however, pose several challenges for packaged goodscompanies and label manufacturers. One of the main reasons for this isthat plastic containers are particularly durable and can withstand moredemanding consumer environments, such as an ice chest, as well aswithstand a drop to the ground of perhaps six feet or more. Further, aplastic container's portability means it can be used and the productconsumed over a long period of time including days or weeks, not hours.

For label manufacturers, this means packaged goods companies preferlabels to be 100% waterproof, 100% scuff-proof, extremely durable,resistant to scuffing and product deterioration, able to withstand dropsof six feet or more without tearing and be aesthetically pleasing to theconsumer's eye and touch for the life of the use of the plasticcontainer. Unfortunately, no state of the art label capable of use withexisting cut and stack labeling equipment offers all of these desiredperformance features in a cost effective manner.

State of the art label solutions for plastic containers generally fallinto four categories, poly/paper, poly/poly, aqueous coated syntheticand ultraviolet (UV) coated synthetic. An example of a state of the artpoly/paper label is a lightweight clear polypropylene film laminated toC1S paper. The clear polypropylene film provides an attractive highgloss appearance. The film lamination also provides durability for scuffprotection and passing drop tests. Due to its incorporation of a paperlayer, however, the poly/paper label is not waterproof. Accordingly,when subjected to humid or wet environments, the label has a tendency tocurl and/or to deteriorate.

An example of a poly/poly label is a lightweight clear polypropylenefilm laminated to a lightweight white opaque polypropylene film printingstock. The clear polypropylene film provides an attractive high glossappearance and durability for scuff protection and passing drop tests.The 100% film nature of the construction provides the label with 100%waterproof properties. However, poly/poly labels are available only inroll fed label form and thus are limited to use by packaged goodscompanies that own and/or operate roll fed labeling equipment. Aspresently manufactured, poly/poly labels are not stiff enough and lacksufficient anti-static properties to run in existing cut and stacklabeling equipment.

An example of an aqueous coated synthetic label is a single layerheavyweight bright white polypropylene film that is aqueous coated. The100% film nature of the construction provides the label with 100%waterproof properties. However, an aqueous coated synthetic label doesnot have the high gloss appearance or scuff resistance properties oflaminated labels and, accordingly, does not provide a complete answer tothe needs of the packaged goods manufacturer.

An example of a UV coated synthetic label is a single layer ofheavyweight bright white polypropylene film printing stock that isultraviolet coated. Again, the 100% film nature of the constructionprovides the label with 100% waterproof properties. While the UV coatedsynthetic label does have a higher gloss appearance and improved scuffand product resistance properties when compared to an aqueous coatedsynthetic label due to the use of an ultraviolet coating, it does notoffer the same degree of gloss and scuff protection as the filmlamination label. This shortcoming along with the high cost ofultraviolet inks and coatings means that UV coated synthetic labels alsofail to meet all the needs of the packaged goods manufacturer.

A need is therefore identified for an improved label for packaged goodsmanufacturers that provides all the desired properties in a costeffective label that is stiff enough and has sufficient anti-staticproperties to reliably and efficiently run in existing cut and stacklabeling equipment.

SUMMARY OF THE INVENTION

In order to achieve the foregoing and in accordance with the purposes ofthe present invention as described herein, an improved cut and stacklabel is provided. That label comprises a layer of polymer film printingstock having a first face carrying a printed message and a second,opposite face. A clear polymer film is laminated to the first face ofthe polymer film printing stock over the printed message. Additionally,a coating of an anti-static formulation is provided over the clearpolymer film and/or over the second face.

Still further describing the invention, the label includes a layer ofadhesive between the clear polymer film and the layer of polymer filmprinting stock. The layer of polymer film printing stock may be madefrom a material selected from a group consisting of polypropylene,polyethylene, polystyrene, polyvinyl chloride, polyethyleneterephthalate, polytetrafluoroethylene, polyvinylidene fluoride,polyvinylidene chloride, polyester, nylon, mineral enhanced polymer andmixtures thereof. The polymer film printing stock may also be opaque,clear, hologram or metallized. The polymer film printing stock may bewhite, black or any other appropriate color that might be selected formarketing purposes. The layer of polymer film printing stock has athickness of at least 0.5 mil and typically between 0.5 mil and 4.0 milin order to provide the desired stiffness for use in existing cut andstack labeling equipment.

The clear polymer film is made from a material selected from a groupconsisting of polypropylene, polyethylene, polystyrene, polyvinylchloride, polyethylene terephthalate, polytetrafluoroethylene,polyvinylidene fluoride, polyvinylidene chloride, polyester, nylon andmixtures thereof. The clear polymer film generally has a thickness ofbetween about 0.5 mil-4.0 mil in order to provide the necessarystiffness, durability and scuff protection to protect the printing onthe printing stock to which the clear polymer film is laminated.

The anti-static formulation generally comprises by weight percent fromabout 2.0-6.0% anti-static agent, 0-3.0% slip agent/wax, 0-0.3% defoamerand the remainder is solvent. Preferably the solvent is water, alcohol(e.g. isopropyl alcohol) or a mixture thereof.

The label may also include an optional dusting or layer of offset powderto further aid in preventing stacked labels from sticking together. Theoffset powder may be applied directly to the clear polymer film when thecoating of anti-static formulation is only applied to the second face,directly to the second face when the coating of anti-static formulationis only applied to the clear polymer film over the first face ordirectly over the coating of anti-static formulation on either or bothfaces. The offset powder may be any powder that functions as a lubricantand aids in separating the stacked labels so as to insure proper andefficient labeling machine operation. Cornstarch is one suitable offsetpowder.

In accordance with yet another aspect of the present invention, a methodof producing cut and stack labels from a web of polymer film printingstock is provided. That method includes the step of applying ink to afirst face of the polymer film printing stock. Additionally, the methodincludes the steps of laminating a clear polymer film to the first faceof the polymer film printing stock over the ink. Still further themethod includes the steps of coating the clear polymer film and/or asecond, opposite face of the polymer film printing stock with ananti-static formulation and cutting individual labels from the laminatedprinting stock. In addition, the method may include the step of applyingan offset powder to the clear polymer film, the second face of thepolymer film printing stock or the anti-static formulation over eitherof those faces.

Still other benefits and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdescription wherein there is shown and described a preferred embodimentof this invention, simply by way of illustration of one of the modesbest suited to carry out the invention. As it will be realized, theinvention is capable of other different embodiments and its severaldetails are capable of modification in various, obvious aspects allwithout departing from the invention. Accordingly, the drawings anddescriptions will be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing incorporated in and forming a part of thespecification, illustrates several aspects of the present invention andtogether with the description serves to explain the principles of theinvention. In the drawing:

FIG. 1 is a schematical edge elevational view of a label constructed inaccordance with the teachings of the present invention; and

FIGS. 2-3 are illustrations of alternative embodiments similar to FIG.1.

Reference will now be made in detail to the present preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to drawing FIG. 1 clearly illustrating the label10 of the present invention. That label 10 comprises a layer of polymerfilm printing stock 12 which may be constructed from polypropylene,polyethylene, polystyrene, polyvinyl chloride, polyethyleneterephthalate, polytetrafluoroethylene, polyvinylidene fluoride,polyvinylidene chloride, polyester, nylon, mineral enhanced polymer andany mixture thereof. Preferably the polymer film printing stock 12 has athickness of at least 0.5 mil and more typically between 0.5 mil-4.0 milin order to provide the necessary stiffness to allow the label 10 to beused in existing cut and stack labeling equipment. The polymer filmprinting stock 12 may be opaque. Of course, other alternatives arepossible including but not limited to clear, hologram and metallized.The polymer film printing stock 12 could be white, black or any othercolor which might be desired by a product packager.

A first face 18 of the polymer film printing stock 12 carries a messageprinted in ink or other means suitable for application to the printingstock. A clear drying adhesive layer 20 is applied to the printed face18 of the printing stock 12 and/or the back side of a clear polymer film22 and the clear polymer film is laminated to the printing stock 12 bythe setting adhesive. The clear polymer film 22 may be made frompolypropylene, polyethylene, polystyrene, polyvinyl chloride,polyethylene terephthalate, polytetrafluoroethylene, polyvinylidenefluoride, polyvinylidene chloride, polyester, nylon and mixturesthereof. Typically the clear polymer film 22 is provided in a thicknessof between 0.5 mil-4.0 mil. Together, the polymer film printing stock 12and the clear polymer film 22 are of a sufficient thickness and strengthto provide the necessary stiffness to help support operation in existingcut and stack labeling equipment. Additionally, the clear polymer film22 provides the desired durability and scuff protection to protect themessage printed on the face 18 of the printing stock 12 from damageduring packaging, shipping, sale, and use by the consumer.

If desired, a cold glue receptive coating may be applied to the backside or second face of the printing stock 12 before the application ofinks and lamination. The coating is a water-based polymeric coating thatis cured by evaporative drying. The coating improves drying during theapplication of the cold glue label adhesive. An example of such acoating is available from RoyMal, Inc. of Newport, N.H.

A first anti-static coating 24 is provided on the exposed face of theclear film 22. The first anti-static coating 24 has a formulationcomprising from about 2.0-6.0% anti-static agent (e.g. Armac 1019,available from Akzo Nobel Surface Chemistry, LLC of Chicago, Ill.),0-3.0% slip agent/wax (e.g. PBI-19559, available from Flint Ink ofAtlanta, Ga.), 0-0.3% defoamer and the remainder is solvent. Thissolvent may be selected from a group consisting of water, alcohol andany mixture thereof. A typical alcohol utilized as a solvent in ananti-static formulation of the type being described is isopropylalcohol. In accordance with yet another aspect of the invention, anoptional offset powder dusting or layer 26 may be applied to the clearpolymer film 22 over the first anti-static coating 24 and/or directly tothe second face of the printing stock 12. The offset powder dusting orlayer 26 may be substantially any powder exhibiting the desiredlubricating properties so as to aid in separating the individual stackedlabels so that they may be fed easily through the labeling machine. Oneuseful offset powder is cornstarch. For example, #375 coated 30 micronpowder available from Oxy-Dry of Itasca, Ill., may be utilized as theoffset powder.

The anti-static coating 24 (and the optional offset powder layer 26 whenused) on the upper face of the label 10 provide sufficient lubricatingand anti-static properties to allow ready separation of stacked labels10 in existing cut and stack labeling equipment. Thus, the labels 10have the necessary stiffness and anti-static properties to operateefficiently and reliably in existing cut and stack labeling equipment.Further, the labels 10 beneficially provide the properties desired bypackaged goods manufacturers utilizing plastic containers. Specifically,the labels 10 are 100% waterproof, extremely durable by being resistantto scuffing and product deterioration and able to withstand drops of sixfeet or more without tearing, and are aesthetically pleasing to theconsumer's eye and touch for the foreseeable useful life of thecontainer. Further, the labels 10 may be manufactured in a costeffective manner competitive in today's marketplace.

Alternative embodiments of the present invention are illustrated inFIGS. 2 and 3. In the FIG. 2 embodiment, the anti-static coating 24 isprovided on the second face of the polymer film printing stock 12opposite the printed face 18. The optional offset powder 26 may beprovided (a) on the first, printed face 18 directly over the clearpolymer film 22, (b) on the second face directly over the anti-staticcoating 24, (c) on both of these faces or (d) on neither face.

In the FIG. 3 embodiment, an anti-static coating 24, 24′ is providedover both faces. The optional offset powder 26 may be provided (a) onthe first printed face 18 over the anti-static coating 24 overlying theclear polymer film 22, (b) on the second face directly over theanti-static coating 24′, (c) on both faces or (d) on neither face.

A method of producing cut and stack labels from a web of polymer filmprinting stock in accordance with the present invention may be generallydescribed as including the steps of: (a) applying ink to a first face ofthe polymer film printing stock or the back side of a clear polymerfilm; (b) laminating the clear polymer film to the first face of thepolymer film printing stock; (c) coating the clear polymer film and/or asecond, opposite face of said polymer film printing stock with ananti-static formulation; and (d) cutting individual labels from thelaminated printing stock. Additionally, the method may also include thestep of (e) applying an offset powder. As illustrated in FIGS. 1-3, thatoffset powder 26 may be applied over the coating 24 of anti-staticformulation on either or both faces, directly to the clear polymer film22 when that film is not covered by an anti-static coating or directlyto the second face of the polymer film printing stock 12 when that faceis not covered by an anti-static coating.

More specifically describing the production method of the embodimentillustrated in FIG. 1, pre-press stage steps include making the printingplates, printing inks and selecting the polymer film for the printingstock.

The printing press stage steps include feeding the polymer film printingstock in web form into the printing press. Specifically, as is known inthe art, the printing press is composed of a feeding unit for feedingstock into the press, a number of print units and a delivery unit fordelivering printed stock out of the press. Each print unit consists of(a) a number of printing cylinders for feeding the printing stockthrough the press, for applying ink to the printing plate and fortransferring ink to the front face of the stock or the back side of theclear polymer film and (b) a drying and/or curing unit that dries theink, coating or adhesive utilizing either hot air drying or ultravioletcuring.

At the first and each subsequent printing unit, ink of particular coloris applied to the first or print face 18 of the polymer film printingstock 12 or the back side of the clear polymer film utilizing theprinting plate. Through the application of ink at each printing unit,the printed image of the label is created.

At the second to last printing unit, an ultraviolet activated adhesive20 is applied with a rubber roller to the first face 18 of the printingstock 12 over the printed image. The polymer film printing stock 12 isthen nipped to a web of clear polymer film 22 that is fed into theprinting press for laminating to the printing stock. Following the nip,an ultraviolet lamp cures the ultraviolet adhesive 20 through the clearfilm 22 while the printing stock 12 moves over a chilling roll tocontrol the temperature of the stock. At the last printing unit, acoating 24 of an anti-static formulation is applied over the exposedface of the clear polymer film 22 utilizing a rubber roller. Thiscoating 24 may be rapidly dried by air circulation or other means ifdesired.

Next, a powder unit applies an offset powder layer 26 to the clearpolymer film 22 over the anti-static coating 24. This offset powderdusting or layer 26 aids in the in-line sheeting operation and thesubsequent feeding of individual labels in the label applying equipment.

Next, the laminated printing stock is delivered, still in web form intoa delivery unit. The delivery unit cuts the stock into individual sheetswith multiple labels 10 on each sheet. These sheets are then deliveredonto a series of skids. Each skid of sheets moves to a post-press stagefor final finishing of the label.

The post-press stage steps of the manufacturing process require eachskid of sheets to be jogged, inspected, separated into increments of1000 sheets, cut, banded and packaged in a box. The sheets are jogged ona jogging machine that vibrates the sheets so that the sheets arealigned to each other for accurate cutting. At the jogging machineseparation of the sheets into lift counts of 1000 sheets is determinedusing a weighing scale.

After jogging, the lift of 1000 sheets is transferred via air tables toa cutting machine that cuts the 1000 sheets into bundles of 1000individual labels 10. After the cutting machine, the bundle of 1000individual labels 10, now in cut and stack form, are packaged togetherand placed in a box for storage and shipment. A bundle of labels 10 canbe packaged in a number of ways including banded, string tied or shrinkwrapped.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. For example, a cold glue receptive coating could beapplied to the back side of the printing substrate before theapplication of inks and lamination. The embodiment was chosen anddescribed to provide the best illustration of the principles of theinvention and its practical application to thereby enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally and equitably entitled.

1. A cut and stack label, comprising: a layer of polymer film printingstock having a first face directly printed with a message and a second,opposite face; a clear polymer film laminated to said first face of saidpolymer film printing stock over said printed message; a coating of anantistatic formulation over said clear polymer film and/or over saidsecond face; and a dusting of offset powder applied to at least oneexposed face of said cut and stack label.
 2. The label of claim 1including a layer of adhesive between said clear polymer film and saidlayer of polymer film printing stock.
 3. The label of claim 1, whereinsaid layer of polymer film printing stock is made from a materialselected from a group consisting of polypropylene, polyethylene,polystyrene, polyvinyl chloride, polyethylene terephthalate,polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidenechloride, polyester, nylon, mineral enhanced polymer and mixturesthereof.
 4. The label of claim 1, wherein said polymer film printingstock is opaque.
 5. The label of claim 1, wherein said polymer filmprinting stock is metallized.
 6. The label of claim 1, wherein saidpolymer film printing stock is clear.
 7. The label of claim 1, whereinsaid clear polymer film is made from a material selected from a groupconsisting of polypropylene, polyethylene, polystyrene, polyvinylchloride, polyethylene terephthalate, polytetrafluoroethylene,polyvinylidene fluoride, polyvinylidene chloride, polyester, nylon andmixtures thereof.
 8. The label of claim 1, wherein said antistaticformulation comprises in weight percent from about 2.0-6.0% antistaticagent, 0-3.0% slip agent/wax, 0-0.3% defoamer and the remainder solvent.9. The label of claim 1, wherein said solvent is selected from a groupconsisting of water, alcohol and a mixture thereof.
 10. The label ofclaim 9, wherein said alcohol is isopropyl alcohol.
 11. The label ofclaim 1, wherein said layer of polymer film printing stock has athickness of at least 0.5 mil.
 12. The label of claim 1, wherein saidlayer of polymer film printing stock has a thickness of between about0.5 mil-4.0 mil.
 13. The label of claim 1, wherein said clear polymerfilm has a thickness of between 0.5 mil-4.0 mil.
 14. The label of claim1, wherein said offset powder is cornstarch.
 15. A method of producingcut-and-stack labels from a web of polymer film printing stock,comprising: applying ink directly to a first face of said polymer filmprinting stock; laminating a clear polymer film to said first face ofsaid polymer film printing stock over said ink; coating said clearpolymer film and/or a second, opposite face of said polymer filmprinting stock with an antistatic formulation; applying an offset powderto at least one exposed face of said web of laminated printing stock;and cutting individual labels from said laminated printing stock. 16.The method of claim 15, further including applying a cold glue receptivecoating to an exposed face of said polymer film printing stock.
 17. Amethod of producing cut-and-stack labels from a web of polymer filmprinting stock, comprising: applying an ink to a back side of a clearpolymer film; laminating said back side of said clear polymer filmdirectly to a first face of said polymer film printing stock; coatingsaid clear polymer film and/or a second, opposite face of said polymerfilm printing stock with an antistatic formulation; applying an offsetpowder to at least one exposed face of said web of laminated printingstock; and cutting individual labels from said laminated printing stock.18. The method of claim 17, further including applying a cold gluereceptive coating to an exposed face of said polymer film printingstock.